Field of the Invention
The present invention relates to an air conditioning system for a vehicle, and more particularly, to an air conditioning system for a vehicle which includes a cold air passageway having a heat exchanger for cooling and a warm air passageway having a heat exchanger for heating inside an air-conditioning case to carry out cooling and heating and which controls to inhale indoor air inside the vehicle, pass the air through the heat exchanger for cooling and discharge the air outside the vehicle in a specific mode.
Background Art
In general, as shown in FIG. 1, an air conditioner system for a vehicle has a refrigeration cycle that includes: a compressor 1 for compressing and discharging refrigerant; a condenser 2 for condensing the refrigerant of high pressure discharged from the compressor 1; an expansion valve 3 for throttling the refrigerant condensed and liquefied in the condenser 2; and an evaporator 4 for exchanging heat between the liquefied refrigerant of low pressure throttled by the expansion valve 3 and air blown to the interior of the vehicle and evaporating the refrigerant to cool the air discharged to the interior of the vehicle due to heat absorption by evaporative latent heat, and that the compressor 1, the condenser 2, the expansion valve 3 and the evaporator 4 are connected with each other via refrigeration pipes. The air conditioner system cools the interior of the vehicle through the following refrigerant circulation process.
When a cooling switch (not shown) of the air conditioner system is turned on, first, the compressor 1 inhales and compresses gas-phase refrigerant of low-temperature and low-pressure while driving by driving power of an engine or a motor, and then sends the refrigerant in the gaseous phase of high-temperature and high-pressure to the condenser 2. Then, the condenser 2 condenses the gas-phase refrigerant into liquid-phase refrigerant of high-temperature and high-pressure by exchanging heat with outdoor air. After that, the liquid-phase refrigerant of high-temperature and high-pressure sent from the condenser 2 rapidly expands by a throttling action of the expansion valve 3 and is sent to the evaporator 4 in a wet-saturated state of low-temperature and low-pressure. The evaporator 4 exchanges heat between the refrigerant and air blown to the interior of the vehicle by a blower (not shown). Then, the refrigerant is evaporated in the evaporator 4 and discharged in a gaseous phase of low-temperature and low-pressure. After that, the gas-phase refrigerant is inhaled into the compressor 1, and then, recirculates the refrigeration cycle as described above.
The evaporator is mounted inside the air-conditioning case mounted to the interior of the vehicle to cool the interior of the vehicle. That is, the air blown by the blower (not shown) is cooled by evaporative latent heat of the liquid-phase refrigerant circulating inside the evaporator 4 and discharged to the interior of the vehicle in a cooled state so as to cool the interior of the vehicle.
Moreover, the interior of the vehicle is heated by a heater core (not shown) which is mounted inside the air-conditioning case and through which coolant of the engine circulates or by an electric heater (not shown) mounted inside the air-conditioning case.
In the meantime, the condenser 2 is mounted at the front side of the vehicle to radiate heat while exchanging heat with air.
Recently, an air conditioning system which carries out heating and cooling only using a refrigeration cycle has been developed. As shown in FIG. 2, such an air conditioning system includes: a cold air passageway 11 and a warm air passageway 12 which are partitioned to the right and the left inside one air-conditioning case 10; an evaporator 4 mounted on the cold air passageway 11 for cooling; and a condenser 2 mounted on the warm air passageway 12 for heating.
In this instance, an air outflow port 15 is formed at an outlet of the air-conditioning case 10 for supplying air to the interior of the vehicle, and an air discharge port 16 is also formed at the exist of the air-conditioning case 10 for discharging air to the exterior of the vehicle.
Furthermore, blowers 20 which are operated individually are respectively mounted at an inlet of the cold air passageway 11 and at an inlet of the warm air passageway 12.
Because the cold air passageway 11 and the warm air passageway 12 are arranged at the right and the left, namely, in the width direction of the vehicle, the two blowers 20 are also arranged at the right and the left.
Therefore, in a cooling mode, cold air cooled while passing through the evaporator 4 of the cold air passageway 11 is discharged to the interior of the vehicle through the air outflow port 15 to cool the interior of the vehicle, and in this instance, warm air heated while passing through the condenser 2 of the warm air passageway 12 is discharged to the exterior of the vehicle through the air discharge port 16.
In a heating mode, warm air heated while passing through the condenser 2 of the warm air passageway 12 is discharged to the interior of the vehicle through the air outflow port 15 to heat the interior of the vehicle, and in this instance, cold air cooled while passing through the evaporator 4 of the cold air passageway 11 is discharged to the exterior of the vehicle through the air discharge port 16.
Additionally, as shown in FIG. 3, an extractor 50 is generally mounted on a trunk of the vehicle in order to discharge the indoor air of the vehicle to the exterior of the vehicle. The extractor 50 is opened by differential pressure between the inside and the exterior of the vehicle.
Therefore, when cold air or warm air is supplied to the interior of the vehicle through the air-conditioning case 10, a predetermined amount of the air (indoor air) circulating inside the vehicle is discharged to the exterior of the vehicle through the extractor 50.
For instance, in a heating mode, warm air is induced to the interior of the vehicle. In this instance, due to VOC and moisture on a window, a predetermined amount of the air (indoor air) of the vehicle is discharged to the exterior of the vehicle through the extractor 50.
However, a conventional air conditioning system cannot utilize the indoor air (heated air) discharged to the exterior of the vehicle through the extractor 50. Furthermore, in order to enhance heating performance, the conventional air conditioning system further includes a chiller (not shown) which is mounted on the cooling cycle of the air conditioning system and exchanges heat between refrigerant and coolant heated by waste heat of electronic units of the vehicle so as to enhance heating performance by increasing refrigerant pressure and temperature. In this instance, the conventional air conditioning system needs additional components, such as the chiller, in order to enhance heating performance.
In addition, the conventional air conditioning system has further disadvantages in that frosting is generated on the evaporator and it deteriorates heating performance under high humid conditions.